I think I've maybe noticed some animation improvements in this one.  The animation still seems a little..."drifty". There are all too many times where the characters seem to move their bodies a little in a two-dimensional sort of way. I imagine that that's sort of characteristic of Flash/Toon Boom animation, but if that's how Arthur's gonna be from now on, we'd better get used to it.

^ That's why I think if they ever attempted another spinoff, it should be about D.W. and her friends/classmates. It seems that more and more episodes put them in the focus. Giving them their own show would make the most sense.

I'm not really sure if that will attract many viewers. It might, but it would probably be targeted towards a younger age demographic, perhaps?